The suspense is going to kill me lol . . .
The US space agency will be tracking the descent with satellites, but its prime craft for the task may not now be in the correct place in the sky.
Engineers have been tackling a fault on the Odyssey satellite and it is no longer in the best observational orbit.
Unless it can be moved back in the next three weeks, Nasa will lose signal to the rover just as it is about to touch down.
This will not affect the outcome of the landing because Curiosity's descent manoeuvres are all performed autonomously, but it will give rise to some high anxiety as everyone awaits confirmation that the $2.5bn mission is safely on the surface.